// htmlToPdf.js
// 导出页面为PDF格式
import html2Canvas from 'html2canvas'
import JsPDF from 'jspdf'
export default {
  install(Vue, options) {
    Vue.prototype.getPdf = function () {
      var title = this.htmlTitle  //DPF标题
        html2Canvas(document.querySelector('#printMe'), {
          allowTaint: true,
          taintTest: false,
          useCORS: true,
          width:1080,
          dpi: window.devicePixelRatio * 4, //将分辨率提高到特定的DPI 提高四倍
          scale: 4 //按比例增加分辨率 
        }).then(function (canvas) {
          let contentWidth = canvas.width
          let contentHeight = canvas.height
          let pageHeight = contentWidth / 592.28 * 700
          let leftHeight = contentHeight
          let position = 0
          let imgWidth = 595.28
          let imgHeight = 592.28 / contentWidth * contentHeight
          let pageData = canvas.toDataURL('image/jpeg', 1.0)
          let PDF = new JsPDF('', 'pt', 'a4')
          if (leftHeight < pageHeight) {
            PDF.addImage(pageData, 'JPEG', 0, 0, imgWidth, imgHeight)
          } else {
            while (leftHeight > 0) {
              PDF.addImage(pageData, 'JPEG', 0, position, imgWidth, imgHeight)
              leftHeight -= pageHeight
              position -= 700
              if (leftHeight > 0) {
              PDF.addPage()
            }
          }
        }
        PDF.save(title + '.pdf')
      })
    }
  }
}
